Regensburg 2013 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 33: Topological Insulators 3 (jointly with HL, MA, and O)
TT 33.7: Vortrag
Mittwoch, 13. März 2013, 10:45–11:00, H16
Controllable magnetic doping of the surface state of a topological insulator — •A. Eich1, T. Schlenk1, M. Bianchi2, M. Koleini3, O. Pietzsch1, T.O. Wehling3, T. Frauenheim3, A. Balatsky4, J.-L. Mi5, B. B. Iversen5, J. Wiebe1, A.A. Khajetoorians1, Ph. Hofmann2, and R. Wiesendanger1 — 1Institute for Applied Physics, Universität Hamburg, Germany — 2iNano, Aarhus University, Denmark — 3Bremen Center for Computational Materials Science, Universitiy of Bremen, Germany — 4NORDITA, Stockholm, Sweden — 5Center for Materials Crystallography, iNano, Aarhus University, Denmark
A combined experimental and theoretical study of doping individual Fe atoms into Bi2Se3 is presented.
It is shown through a scanning tunneling microscopy study that single Fe atoms initially
located at hollow sites on top of the surface (adatoms) can be incorporated into subsurface layers
by thermally-activated diffusion. Angle-resolved photoemission spectroscopy in combination with
ab-initio calculations within density functional theory suggest that the doping behavior changes from electron donation for the Fe
adatom to neutral or electron acceptance for Fe incorporated into substitutional Bi sites. According
to the calculations, these Fe substitutional impurities
retain a large magnetic moment thus presenting an alternative scheme for magnetically doping the
topological surface state. For both types of Fe doping, we see no indication of a gap at the Dirac
point.
T. Schlenk et al., arXiv: 1211.2142v1 (2012) [cond-mat.mtrl-sci]
J. Honolka et al., PRL 108, 256811 (2012)